In optical fiber communications there is a need to ascertain the location of any faults within an optical fiber so that these faults can be repaired, if needed. Currently, this must be done by disconnecting the optical fiber from a transmitter/receiver so that the optical fiber can be diagnosed using a separate testing apparatus. Optical time-domain reflectometry (OTDR) is commonly used to locate any faults (e.g. fiber breaks) in today's fiber-optic networks. The use of a separate testing apparatus to locate faults within an optical fiber is time consuming and costly and requires a trained operator.
The present invention provides an advance over the art of optical fiber fault location techniques and optical fiber communications by providing an optical fault location apparatus which can be built into a fiber-optic transmitter so that there is no need for a separate testing apparatus for locating any faults within an optical fiber. According to the present invention, a single vertical-cavity surface-emitting laser (VCSEL) can be used as an optical transmitter to transmit information through an optical fiber, and, when needed, can be quickly and simply converted into an in-situ fault location apparatus to locate any faults within the optical fiber. Then, just as quickly, can be reconverted to transmit additional information through the optical fiber. This dual functionality can allow for automation of the fault location process, and can reduce the cost and time required for fault detection in fiber-optic networks.
Additionally, the present invention can be used to form a stand-alone optical fault location apparatus that is simpler in construction than present-day devices which utilize a separate laser and photodetector.
These and other advantages of the present invention will become evident to those skilled in the art.